An oral formulation of a macrolide compound, namely tacrolimus with useful immunosuppressive activity, has been prepared as a solid dispersion composition, which possesses a rapid-release characterization, by using polymers such as hydroxypropylmethyl cellulose and a disintegrator (see for example EP 0 240 773). Owing to the presence of the disintegrator therein, it is a rapid-release formulation. It has been appraised highly in the clinical field owing to its high absorbability. In clinical practice, alternatively, the emergence of an oral tacrolimus formulation with a sufficient long action and excellent oral absorbability has been expected. However, it is the state of the art for a person skilled in the art that the absorbability of a pharmaceutically active agent given orally in a manner as a sustained-release formulation is generally reduced and/or that a non-negligible variation of the absorbability is observed. The inventors of the invention have carried out a lot of investigations. Consequently, the inventors have invented sustained-release formulations of macrolide compounds, the representative of which is tacrolimus, characterized in that macrolide compound is excellently absorbed orally and/or that variation of its absorbability is suppressed.